Triggers or buttons are commonly used on electronic devices. For instance, triggers are employed on mobile computing terminals, bar code scanners, cellular phones, portable digital assistants (PDAs), etc. The trigger is used to initiate certain functions on the device. For instance, the trigger may activate a module to capture bar code information. The module may be a laser based bar code scanner or an imager. The trigger may also activate a speaker module for telephonic communication, it may activate a data transfer function or it may be used to navigate through menu options on a display.
FIG. 1 shows a typical conventional trigger assembly for a mobile terminal. The assembly consists of several mechanical type components that are utilized to actuate electrical switch assembly 8 upon the depression of a trigger button 4. Switch assembly 8 has two switch elements 8a and 8b to activate two functions on the mobile terminal. Switch assembly 8 can include contacts 5 or wires/flex that connect to circuitry within the mobile terminal. A trigger housing 9 connects trigger button 4 with mobile terminal housing 10. A trigger bezel 6 connects trigger button 4 with trigger housing 9. A leaf spring 3 acts to restore trigger button 4 to its initial position after trigger button 4 is depressed. Sealing in terms of electrostatic discharge (ESD), water, and dust, requires the addition of gaskets to the trigger assembly.
The above-described trigger assembly has a number of shortcomings. The trigger assembly requires a user to assert a fixed amount of force and stroke in order to activate the trigger. Also, the trigger assembly must include gaskets to environmentally seal the terminal. Even with such gaskets, water and debris may still enter the terminal. In addition, the trigger assembly has a limited number of life cycles due to wear on the various moving parts. In addition, the trigger assembly requires a relatively significant amount of labor to manufacture.